Electric clock



Ja n. 5, 1937. J. B ERTl 29 41 ELECTRIC CLOCK Filed Feb. 19, 1935 15% INVENTOR cfoseph Berta BY MBW A ORNEY Patented Jan. 5, 1937 UNITED STATES PATENT OFFICE Application February 19, 1935, Serial No. 7,185

3 Claims.

This invention relates to the electromagnetic means for tensioning the driving spring of an electric clock and the objects of the invention are to provide simple, practical and inexpensive mechanism of this character, which will take up but small space, be quickly and easily installed, be reliable and positive in its operation and operate with very low current consumption.

These and other objects, as will appear, are all attained by the novel features of construction, combinations and relations of parts hereinafter set forth and broadly covered in the claims attached.

The drawing accompanying and forming part of the following specification illustrates practical and at present preferred embodiments of the invention, but it is to be understood that changes and modifications may be made all within the true intent and broad scope of the invention.

Fig. 1 in the drawing is a broken and part sectional view illustrating one form of the invention as applied to a more or less standard form of clock construction.

Fig. 2 is an enlarged broken sectional detail of the solenoid structure and spring lever engageable by the solenoid core.

Fig. 3 is a generally similar view illustrating modifications in the magnet structure.

In Fig. 1, a more or less conventional design of clock movement is indicated at 5, in which the last gear of the train at 6, is equipped with a ratchet 1, engaged by a driving pawl 8, on an arm 9, of lever l0, pivoted on the center at H, and tensioned by a helical spring I2.

35 The spring lever I0 is shown as carrying at its free end a contact point I3, positioned for engagement by a live or actuating contact.

Actuation of the so-called live contact is effected by a solenoid consisting in the illustration of a magnet winding I4, on the hollow spool center l5, in which operates the solenoid core l6, carrying contact ll, opposed to the lever contact l3.

In the first form of the invention illustrated, the spool center I5, is a metallic tube and one end of the winding as indicated at I8, in Fig. 2, is mechanically and electrically connected with this metallic center tube. The opposite end of the winding at I9, is brought out beneath a clamp nut 20, Fig. 1, on the end of a terminal screw 2 I, holding beneath its head a spring strip 22, in engagement with an insulated terminal 23, on the clock case 24.

The terminal screw is utilized as a mount for the solenoid by providing one head 25, of the magnet spool with an extension 26, held by the nut 20, against a spacing bushing 21, which engages the back of a mounting lug 28, on the movement plate. An insulating washer 29 beneath the spring strip- 22 holds the latter out of contact with this mounting lug.

As shown in Fig. 2, the end of the core which carries the contact I'l, may be formed as a separate part, 33, screwed or otherwise connected at 31, with the end of the main body of the core Hi. In manufacture, the main portion 16 may be of good magnet steel and the attached part 30, be of brass or the like, carrying the contact I? of tungsten or other suitable material for cooperation with similar contact l3. Both the main core l6 and the attached head portion 30, have flanges 32 and 33, forming stops, limiting stroke of the solenoid core. The flange 32 on the magnet core piece l6, also in the illustration, serves as an abutment for a core retracting spring 34. This latter is indicated as having a bearing at its inner end at 35, against the end of the metallic spool center and the ends of this tube are shown as upset or flanged outwardly at 33, to secure the spool heads firmly in place and also in this particular instance, to provide a widened end face for contact by the end of the spring 34. The flange 33 at the contact end of the core abuts the flanged end 36, of the tube when the core is retracted by the spring and. hence makes solid electrical contact therewith in the retracted position of the core.

The construction of the solenoid core in two parts connected by a screw joint, facilitates assemblage as the spring 34 may be slipped over the magnetic portion l6, and then upon connection of the two parts by the screw 3 I, the core structure will be completed and at the same time, it will be secured within the spool and with the sliding movement permitted by the end heads or flanges 32, 33. In this mounting also, the inner end of spring 35, will be brought into engagement with the end of the metallic center and thus a yielding resilient connection established between the core and the tube in which it is guided.

The core may be nickel plated, if desired, to assure easy sliding movement of the same within the spool center and to effect good electrical sliding contact between the core and guiding tube.

In Fig. 1, the case is shown as having a terminal 31, for connection with what would ordinarily be the grounded side of an electrical circuit. It will be seen that with the insulated terminal 23, connected with the other, or so-called live side of the circuit, current will be carried through spring strip 22, terminal screw 2|, and wire end I9, to the magnet coil and that from the inner end of this coil, current will be carried at l8, Fig. 2, to the metallic spool center and from this center to the core itself, so that as soon as spring l2 draws the lever Ill, over far enough to engage contact I? with the core contact H, the circuit will be completed and the magnet energized to draw in the core and snap the lever over in a spring tensioning direction. The action is direct and immediate and the inertia of the lever is sufiicient to effect automatic interruption of the current at the end of the core stroke.

While the construction shown in Fig. 2, with the metallic center sleeve,.is preferred, because of the ample electrical contact between core and sleeve, a construction like that shown in Fig. 3, may be employed with the center sleeve 15a, of insulating material and contact with the core made by connecting the inner end of the winding at lBa, with a metallic end head 25a and having the spring 34, bear against this metallic end head. In this case, the spring 34, is relied upon entirely to carry current to the solenoid core, whereas in the former case, the current has a number of paths and resistance in circuit is thereby kept at an absolute minimum. The! spring 34, to an extent, cushions the inward snap ol' the core, but if desired, a rubber or similar bumper or bumpers 38, (Fig. 2), may be interposed between the core and spool structure to cushion the movement of the core in either or both directions and prevent harmful shock being imparted to the movement.

What is claimed is:

1. Electromagnetic spring tensioning means, comprising a solenoid spool having end heads and a center tube of conducting material, one of said end heads having an extension of insulating material, a winding on said spool between said end heads, a mounting lug, screw means securing said insulating head extension of the spool to said mounting lug, said winding being connected at one end with said screw means and electrically connected at the opposite end with the conducting center tube of said solenoid spool, a solenoid core operating in said center tube and in electrically conducting relation therewith, a contact on one end of said core and a spring tensioned member provided with a cooperating contact.

2. Electromagnetic spring tensioning means, comprising a solenoid having a center openended sleeve, a winding on said sleeve and a solenoid core operable in said sleeve, said core consisting of a main portion of magnetic material having a flange at the outer end limiting movement of the same into the winding and a lesser portion of non-magnetic material and provided with a flange at the outer end limiting movement of the core in the opposite direction out of the winding, a spring about the core be-- tween the first mentioned flange and the adjacent end of the winding for drawing the core out of the winding, said core portions having engaging means at their inner ends for securing the same together within the winding after said portions are inserted into engagement through the opposite open ends of the center sleeve, a contact carried by the non-magnetic portion of the core and a spring tensioned member provided with a contact for engagement with said core contact said contacts forming parts of an energizing circuit for said winding.

3. Electromagnetic spring tensioning means, comprising a solenoid having a center tube, a winding about said center tube, an end head at one end of said tube and a solenoid core operating in said tube, an integral extension projecting from said end head to one side of the solenoid, a mounting lug, screw means fastening said end head extension to said mounting lug and fixing the solenoid in supported relation on said mounting lug, a spring tensioned member operable by said solenoid core and electrical connections for the solenoid controlled by said core and spring tensioned member.

JOSEPH BERTI. 

